TY  - JOUR
AU  - Khalaf, M.
AU  - Kohl, S.
AU  - Klumpp, E.
AU  - Rice, J.
AU  - Tombácz, E.
TI  - Comparison of Sorption Domains in Molecular Weight Fractions of a Soil Humic Acid Using Solid-State 19F NMR
JO  - Environmental Science & Technology
VL  - 37
SN  - 0013-936X
CY  - Columbus, Ohio
PB  - American Chemical Society
M1  - PreJuSER-30959
SP  - 2855 - 2860
PY  - 2003
N1  - Record converted from VDB: 12.11.2012
AB  - Humic acid was fractionated into eight different molecular size components using ultrafiltration. Solid-state CPMAS C-13 NMR demonstrated that fractions larger than 100 000 Daltons were primarily aliphatic in character,while fractions smaller than 30 000 Daltons were predominantly aromatic in character. Solid-state F-19 NMR examination of the sorptive uptake of hexafluorobenzene (HFB) by HA and each of the fractions gave spectroscopic evidence for the existence of at least three sorption sites in the smaller molecular size fractions, while two predominant sorption sites could be established in the larger molecular size fractions. Sorbed HFB displayed higher mobility in the smaller, more aromatic fractions while HFB in the larger, more aliphatic fractions displayed lower mobility. The relative mobilities of HFB in each sorption domain suggest that the rigid domain may be composed of aliphatic carbon rather than aromatic carbon moieties. In larger size fractions, this domain may be the result of rigid, glassy regions composed of aliphatic molecules or side chains.
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000183973700023
DO  - DOI:10.1021/es0206386
UR  - https://juser.fz-juelich.de/record/30959
ER  -